The adapter is designed to screw onto a standard (non-professional) tripod to which you can attach your standard GoPro.

The model is designed around a captured ¼-20 nut in the base and a spot to insert a m5 nut in the side.  v6 of the model can be printed without supports.  Be sure to set a pause in the printjob at the correct layer to insert the ¼-20 nut.

I recommend printing in PETG.